DESCRIPTION: The work proposed focuses on a number of questions concerning the diagnosis, natural history, study design and role of markers in the prognosis and tracking of prostate cancer. Adaptation and development of statistical methodology is central, but useful results are targets, based on a number of data sets available to the investigator. Aim (i) deals with the shift in biomarker growth rate with the advent of frank diagnosis and involves the study of cases and controls in longitudinal tracking, with special